tothe
Letters
Dear
coffee
and
serum
LDL-cholesterol
tation provided is that consumption of decaffeinated no coffee causes an increase in LDL cholesterol. worthwhile to suggest that consumption ofcaffeinated
Sir:
The role of coffee rotic coronary artery
consumption in the etiology of atheroscledisease has been the subject ofa long debate
easily
the
encompassing
troduction
past
of a variety
rations
now
in use.
30 y. This
of brewing
The
recent
debate
predates
methods
report
and
This area ofinquiry is notable for its inconsistency It seems clear that caffeine, despite its indictment
identify
decaffeinated
(5, 7, 8). How
these
other
Several
then
might
as being
the study
aspects
ofthe
need
with the continued
design
further
than
by Superko
and
coffee
et al differ
from
issue of compliance. drinking of subjects’
the control
group,
decaffeinated
coffee
the
with
being
continued
ofthe
toward
Superko
this end.
The
The study design usual caffeinated
with
abstinence
experimental
consumption
dictated coffee
ofcaffeinated
drinkers,
and
or no-coffee
creasing
interesting, in the same
with other direction.
usual consumption rate, Apparently, at least one
or did subject
their was
groups
may
be interpreted
also
coffee’s
The
report
effect
is mediated
by Superko
of this
brewing
However,
tically
different
terol.
Most
none from
studies
of these the baseline
of coffee
in lipid
concentrations
another
group’s
differences
topic.
method,
To
and
with
values.
The
concentration
consumption
the
to the
possibly
results
suggest
coffee
from
is left wondering groups the
no-coffee 604
around
decrease
baseline whether
an average in LDL
groups?
values the results
for the
with
in the
than
is the significant
the type
study
the
beans
steps
substance? explain
Any
Can the
the
recommendation
the grounds
of health and
phenols
differences?
What
of one
concerns,
explanation
ofthe
should
NY
Bassett
add
con-
a cholesterol-
in certain
types
of coffee
results
be if the
the
with caffeine
of coffee
await
observations
Research
Usually,
of coffee
would
sample form
the de-
factor for used in the
describing. that
the
bean,
the removal
can be hypothesized
com-
consumed,
of coffee
is worth
suggests
serum lipase ratio. decaf-
over
and one
another
on
the confirmation, by Superko et al. Thomas A Pearson
Institute
13326-1394
References
coffee
is the
The
one
between cause
caffeinated-coffee
trend?
raising
Cooperstown,
with
it. Thus,
variation What
What
process
The Mary Imogene One Atwell Road
choles-
caffeinated
represent
of no change.
cholesterol
Which
associated
stituents.
expansion,
or no coffee has as large a decrease from baseline values of LDL cholesterol associated with it, whereas decaffeinated coffee has
an increase
or both in lipo-
the changes
rather
that
of cups
between
of LDL
values
in de-
enzymes. emphasizes
number
one-
to be statis-
compare
baseline
by these
et al correctly
decaffeinated
LDL cholesterol
appear
only one decrease
is as-
decreased by 0. 1 1 mmol/L in the caffeinated-coffee and no-coffee groups, but increased by 0.12 mmol/L in the decaffeinated-coffee
group.
effect
coffee
their
that con-
hepatic triglyceride lipases is unique and
caffeination process should be added as a possible analysis. In this regard, the method ofdecaffeination
rate change up or down? unable to continue. The
differently.
coffee’s
increasing effect on
choles-
a less
com-
degree of crossover between groups would be essential interpretation of study results. Second, the magnitude and significance ofdifferences study
It seems provide
Thus,
to continue
in the
by a fall in LDL
drinkers.
or as or
6% difference,
protein lipase probably should be reflected in increased triglycerides. A significant increase in hepatic triglyceride probably should cause an increase in the HDL2-HDL3 Neither were observed. Thus, it seems speculative that
same coffee beans were used-one sample without caffeine?
able
coffee It seems coffee
cholesterol
drugs usually affecting A clinically significant
Were
subjects
The
would
lipoprotein lipase and is unclear. This opposite
the decaffeination
decaffeinated-coffee
half
explanations
sumed, but what was the compliance in the other two groups? Was the abstinent group able to abstain? Earlier studies of coffee consumption observed the need for subjects randomly assigned to abstinence to be allowed some form of hot beverage (9, 10).
the
cholesterol.
for by a rise in LDL
sided interpretation of findings. Finally, the significance of decaffeinated
plexity
to
in LDL
of alternate
feinated
first
or change
groups.
a fall
in the caffeinated-
sideration
lipase
regular
interpretation
clarification
characterized pliance
by the popular
elevation (2-5). One coffee, is, in fact, the studies have failed to
worse
causes
is half accounted
terol
namely desubstances cholesterol. of findings.
studies?
et al study deals that
coffee
then,
decaffeinated-coffee
et al (1) focuses
of coffee, it contains (LDL)
media, is not responsible for cholesterol cholesterol-raising component of boiled lipid-soluble fraction (6). Moreover, other
no coffee
in-
prepa-
coffee
by Superko
on one of these more recent preparations caffeinated coffee, and the concern that that might raise serum low-density-lipoprotein
the
concentrations
for and
interpre-
Am J C/in Nuir
l992;56:604-l0.
1. Superko
HR. Bortz W, Williams PT, et al. Caffeinated and decaffeinated coffee effects on plasma lipoprotein cholesterol, apolipoproteins, and lipase activity: a controlled, randomized trial. Am I CIin Nutr l99l;54:599-60S. 2. Thelle DS, Heyden 5, Fodor 1G. Coffee and cholesterol in epidemiological and experimental studies. Atherosclerosis 1987;67:97103. 3. Davis BR, Curb D, Borhani NO, et al. Coffee consumption and serum cholesterol in the Hypertension Detection and Follow-up Program.
Printed
Am
I Epidemiol
1988;128:124-36.
in USA. © 1992 American
Society
for Clinical
Nutrition
Downloaded from https://academic.oup.com/ajcn/article-abstract/56/3/604/4715434 by McMaster University Library user on 03 February 2019
Decaffeinated
Editor
LETTERS 4. Shirlow MI, Mathers CD. Caffeine consumption lesterol levels. Int I Epidemiol 1984; 13:422-7. S. van Dusseldorp M, Katan MB, Demacker PNM.
and
TO
serum
Effect
cho-
of decaf-
Reply Dear
I would
like
to respond
to the
comments
of Pearson
for the
authors. First, our has no effect
randomized trial on the lipoprotein
point
was
Second, is the
trial
involved
number
emphasized
Pearson
sign
of any
results
was
of randomization
by
classic
group
assignment.
of subjects
in their suspicion of assignment to this group. was developed over 2 y and underwent intense
in the decaffeinated
(NIH)
group group
Questionnaires
that
ofHealth
cal-
as to the
or decaffeinated-coffee
vealed
Institutes
The
power
correct design
the National
Our
were blinded
caffeinated-
de-
participants.
subjects placed in the no-coffee assignment and the decaffeinated
of their
60%
Trial
investigation.
many
and subjects into
those group
issues.
clinical with
determined
The investigators
suspicious
good
coffee study.
section.
trial-design
design
of participants
that caffeinated measured in our
discussion
several
a randomized
groups. Certainly, were aware oftheir
indicates variables
in the
addresses
foundation
culations.
was
Third,
the
was
issue
of compliance
determined
Coffee Dear
DS. Coffee
and
article
coffee
Study
by the
is an important difference
lipoprotein
one.
by
Superko
diet
records.
and ingestion There
groups. There Fourth, the
NIH-funded
between
groups.
clinical leading variables
returned
was
was
no
study This
at each
determined
Compli-
between
the
to test
is the purpose
ofhaving
calculations the main
were performed to design hypothesis. We believe that
et al (1)
on
coffee
and
regular
could
take
of coffee drinking led to a decline 2) Under Laboratoryprocedures C concentration was formula for calculating LDL-C
terol,
C is cholesterol, and
TG
In Results observed
coffee
After
as before.
total HDL
With
the position
that
in LDL-C. it is clearly
stated
Berkeley,
C - (HDL-C
+
they
the no-
the cessation that
LDL-
practice. The is as follows:
TG/5)
is high-density-lipoprotein
choles-
is triglyceride. it is stated
for changes
that
Superko
Center
Berkeley Laboratory of California CA
94720
Reference I . Superko HR, Bachorik cholesterol measurements.
“No
in concentration
3)
In Table are
PS, Wood PD. High-density JAMA l986;256:27 14-7.
significant of plasma
differences triglycerides,
1 (Baseline
definite
lipoprotein
with
the
in the
other
small, 4
237
but
)
intakes
are
two
of the
groups.
Their
Admittedly, ofthe
6)
and
two measurements completion of the
three
TGs
the
differences
Cups per day are described as follows: mL of fluid coffee” as opposed to the
Only upon
calculated groups)
decaffeinated-coffee
group are
higher,
values are Also, their
differences
that
are
is surprising.
“each cup equal to generally accepted
definition of a cup constituting 150 mL. 5) Statistical analyses were applied to group tween baseline and end-of-study measurements lowing each subject to be his own control.
were
the
are higher, their HDL-C B values are higher.
lower.
it is the consistency
or apo-Asubjects.” If ofthe equa-
could
characteristics
differences
their total C concentrations lower, and their apolipoprotein carbohydrate
calculated. This is the usual the LDL-C concentration =
in
lipoprotein
H Robert Research
as compared
one
groups
subtle
total cholesterol, HDL cholesterol, HDL2 cholesterol, I for the decaffeinated-coffee group vs the control there were no differences in any ofthe components
lipoprotein
showed
(LDL-C).
to drink
of change
that could answer with smaller pop-
ulations may lack the statistical power to reveal differences induced by components of coffee.
all,
drinkers
in low-density-lipoprotein-cholesterol at least
addressed
cholesterol
1, the caffeinated-coffee
continued
was
control
a trial studies
there
group
between
for significance
a decline
in Figure
and
in compliance
between groups. of the study that
was
Compliance
trials. Testing for a change from baseline can be misbecause it does not take into account the multitude of that can alter lipoprotein measurements (1). The power
Lawrence University
by
visit.
by questionnaire
difference
was no crossover statistical design
in this
were
We believe
in weight
no coffee
The trial review by
group
Section.
dispensed
with
why,
where
Br
coffee
tion for the calculation of LDL-C, how value have shown a significant increase?
merely
cholesterol.
SF, Arnesen E, et al. The Tromso Heart Study: and serum lipid concentrations in men with a randomized intervention study. Br Med I
cholesterol raises many questions requiring further explanation before the authors’ conclusions can be accepted with confidence. 1) From the data presented it is impossible to understand
coffee
and serum
10. Forde OH, Knutsen coffee consumption hypercholestcrolaemia: 198S:290:893-S.
Cholesterol
Sir:
The
9. Arnesen E, Forde OH, Thelle Med I 1984;288:1960.
re-
our investigation is the only US coffee investigation funded the federal government and not by commercial interests. ance
8. Fried RE, Pearson TA, Levine DM, et al. The effect offiltered coffee consumption on plasma lipids: results ofa randomized clinical trial. JAMA 1992;267:81 1-S.
to TA Pearson
Sir:
This
605
EDITOR
differences instead
of lipids were obtained: study. Thus, one does
not
beof alat entry know
Downloaded from https://academic.oup.com/ajcn/article-abstract/56/3/604/4715434 by McMaster University Library user on 03 February 2019
feinated coffee versus regular coffee on serum lipoproteins. Am I Epidemiol 1990; 132:33-40. 6. Zock PL, Katan MB, Merkus MP, et al. Effect ofa lipid-rich fraction from boiled coffee on serum cholesterol. Lancet 1990;335:l23S-7. 7. Bun- ML, Gallacher JEI, Butland BK, et al. Coffee, blood pressure and plasma lipids: a randomized controlled trial. Eur I Clin Nutr l989;43:477-83.
THE